This invention relates to a method of producing high purity calcium and magnesium carbonate. The invention relates particularly to the production of specific crystalline forms of high purity calcium carbonate from relatively impure calcium source material.
Calcium carbonate and magnesium carbonate are natural carbonates which are present in large quantities particularly in calcitic and dolomitic limestone. In raw impure form these products are used in various industries including the mining and cement industries. In purified form calcium carbonate is used in the production of white paint, in toothpaste, paper coating and as a filler in pharmaceutical products. Likewise, in pure form magnesium carbonate finds application in various fields, e.g. in the steel industry.
Despite their natural abundance pure calcium carbonate and magnesium carbonate are relatively expensive products due to the difficulties and expenses associated with the conventional purification methods.
It is an object of the present invention to provide a new method for producing reprecipitated calcium carbonate from a natural source material containing calcium and optionally also recovering magnesium carbonate therefrom, if the latter is present in the source material.